This is probably the best enactment of the future scenario that will play out when Yellowstone erupts again. They say in the introduction, that "this is a true story...it just hasn't happened yet"....but it has...640K years ago. Geologists see in the grey rock layers to the east of Yellowstone, black layers which formed about every 6ooK years from the ash during past Yellowstone eruptions. We're 40K years overdue. This film shows how [they] will cover up the severity until it's too late.